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Tony Leukering

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Everything posted by Tony Leukering

  1. In Red-breasted Nuthatch, males have black crowns contrasting strongly with the gray-blue back, while females have crowns nearly concolorous with the back.
  2. https://cobirds.org/CFO/ColoradoBirds/InTheScope/44.pdf Accipiters do not have dark throats, nor do they sport wide, dark malar stripes.
  3. I have absconded with the photo and cropped it and darkened it to remove much of the over-exposed aspect. As can be seen here, the bill is shallow (top to bottom) and all black, which rules out Herring Gull. Additionally, the primaries are not black and the inner webs of the secondaries are pale -- both features of Thayer's Gull. I have no problem with Thayer's Gull [or "Iceland Gull (Thayer's)" in eBird parlance] as the ID of that bird.
  4. Using bill color to ID female goldeneyes requires first ageing the bird (see here). In the first added photo, the bird second from right is an immature (darker eye), thus the bill color does not provide evidence for or against hybridization. The head shape looks very good on that bird for Barrow's, but head coloration seems a bit problematic, more like the warmer brown of Common than the colder brown of Barrow's, though certainly at least leaning toward Barrow's color. However, the lighting and shimmer make accurate assessment of coloration -- particularly with the slightly different head angles -- problematic, at best. Personally, I'd leave this bird as of uncertain ID if this were the only evidence. The trailing bird is an immature Common (again, dark eye). On the male in the added photo (and in the original photo), the shape of the loral spot is intermediate between that of the two parental species, as is the scapular pattern.
  5. Ageing the bird is critical to understanding the importance or relative lack thereof of the not-wholly-yellow throat and the ghost of Myrtle face pattern (supercilium, ear surround). The greater coverts with their wide, white tips and with all being, essentially, identical should tell us that this is an adult. Since it's a male (breast coloration), the sloppy head pattern and coloration should put the icing on the intergrade cake. I would lay high odds that this bird is a back-cross with Audubon's (that is, the progeny of an Audubon's with an intergrade, or F2) and might be one more generation removed from the hanky-panky (F3). See hybrid index explanation.
  6. immature male -- incoming black male feathers
  7. I have no problem with the "darker" bird being a Herring, as lighting and angle can greatly alter the apparent darkness of the mantle. The white primary tips are just too small to be those of a Thayer's (aka Iceland) Gull and the shape seems fine for Herring.
  8. Beware of Tav x Richy intergrades -- they are not all that rare and could easily account for this bird's pale underparts
  9. Time of year -- Juv Loggerhead don't look anything like this after Jul or Aug.
  10. Both definitely Lesser (see below) https://cobirds.org/CFO/ColoradoBirds/InTheScope/21.pdf http://cowyebird.blogspot.com/2018/02/greater-scaup-ebird-problem-child.html
  11. Reddish on underparts not a deal-breaker for Harlan's.
  12. https://cobirds.org/CFO/ColoradoBirds/InTheScope/33.pdf
  13. I agree with akiley: There's nothing about the bird, other than coloration, that is odd for Herring Gull (smithsonianus). If it were a hybrid, such as Herring x Glaucous, there would be more intermediate features.
  14. If it's a Cackler, the best bet for the rounded head shape and dark breast would be Taverner's. However, that subsp typically has a thicker-based bill giving something of a "roman-nosed" appearance. Unfortunately, Richardson's and Taverner's have apparently met and are now mixing genes, making the differentiation of anything but classically-shaped individuals a bit problematic. BTW, Tav is the largest of the four subspecies of Cacklers.
  15. Common Tern: Very wide dark trailing edge to the primaries from below Outer primaries notably darker (on top side) than inner primaries (this feature caused by a very different wing-molt strategy in Common vs. Arctic)
  16. Mottled Duck flags in Pinellas County because most of the birds that are called Mottleds are actually hybrid Mallad x Mottled Duck (see here). Thus, the county filter was changed to not allow reports of the species without photos or good descriptions.
  17. There are many subspecies of Dunlin, which is the main reason behind the large variation in size. Not many other arctic-breeding shorebird species are polytypic, probably due to the nature of their migrations.
  18. Mergansers -- https://cobirds.org/CFO/ColoradoBirds/InTheScope/82.pdf Note also that "peep" does not equal "shorebird." "Peep" is a term that covers the very smallest sandpipers: Least, Semipalmated, Western, White-rumped, Baird's, Spoon-billed, and everything with "stint" in its name.
  19. Adult Thayer's, as in the pic provided by AlexHenry, generally has a bicolored bill, with the area beyond the gonys being yellow and the rest having a gray or olive cast, at least in winter.
  20. I agree about the ID, but one should beware of orange-billed Commons (see here).
  21. Immature males have facial patterns like that of females, and I haven't yet noted when that plumage is changed out. That fact could account for the apparently skewed sex ratio of the birds in the pix.
  22. https://cobirds.org/CFO/ColoradoBirds/InTheScope/82.pdf
  23. Also the partial dark band along the base of the bill (American = full band, Eurasian = no band)
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